Corsi ratings are the difference between the number of shots directed at goal (shots on goal, missed shots and blocked shots) in 5 on 5 situations for a given team and their opponents when a given player is on the ice. It is a strong measure of puck possession. There are several factors independent of the player in question that I have attempted to remove. They are team effects - as good teams will tend to possess the puck more than bad ones regardless of which player is on the ice and the player’s usage, namely if he starts a lot more shifts in the offensive or defensive zones.

Here are the worst 20 team and zone adjusted Corsi ratings from the 2009/10 season:

2009/10 Worst Team And Zone Adjusted Corsi Ratings

Rank

Player

Team

Adjusted Corsi

1

Jason Strudwick

Edm

-228.04

2

Colton Orr

Tor

-224.96

3

Steve Eminger

Ana

-199.68

4

Rob Niedermayer

NJD

-193.88

5

Karlis Skrastins

Dal

-192.72

6

Lauri Korpikoski

Phx

-168.48

7

Kirk Maltby

Det

-168.04

8

Ethan Moreau

Edm

-164.44

9

Trevor Daley

Dal

-162.72

10

Zbynek Michalek

Phx

-162.68

11

Ryan Johnson

Van

-162.04

12

Keith Ballard

Fla

-156.88

13

Tanner Glass

Van

-148.04

14

Ed Jovanovski

Phx

-146.68

15

Ben Eager

Chi

-144.76

16

Dustin Brown

LAK

-138

17

Maxim Lapierre

Mon

-137.08

18

Michal Handzus

LAK

-137

19

Francois Bouillon

Nas

-134.92

20

Rick Rypien

Van

-134.64

For this list, I only considered players who played 50 or more games because it is unfair to apply a team adjustment to a player who barely played with that team. A player needs to have played a significant enough number of games for this ranking to be meaningful.

This list of 20 players put up some of the weaker performances in 2009/10.

At the top of the worst player list by this metric is Jason Strudwick, a player who inexplicably remains employed by the Oilers due to the fact he is a good teammate and a hard worker and that seems more important than his ineffectual play in the minds of Oiler management.

Colton Orr is next. He is an ineffective checking forward in Toronto.

Steve Eminger had a poor year on the Anaheim defence and he is third worst.

Rob Niedermayer is no longer an effective checking forward, but remains employed due to his last name as much as any other reason. He will be playing in Buffalo this season and that is his third team in three years.

Karlis Skrastins is the final in the group of five who have a lead over the rest of the league. He failed in Dallas this year.

Next up is Lauri Korpikoski in Phoenix and Kirk Maltby, the once effective Detroit checking forward.

Ethan Moreau had a poor year in Edmonton, but will have a chance to ply his trade in Columbus this year. Trevor Daley was a poor Dallas defenceman.

Zbynek Michalek managed to get a big contract out of the Pittsburgh Penguins despite a poor season. He was part of a much improved Phoenix Coyote team and got credit for it that he didn’t deserve. I expect that the Penguins will regret that signing.

Ryan Johnson was a failed Vancouver Canuck checking forward and he comes next. He is followed by new Canuck Keith Ballard, who struggled as the Florida shutdown defenceman. He had the worst raw Corsi in the league and this was due to a combination of a poor team, a tough defensive assignment and a poor individual performance. Tanner Glass is the third consecutive player who is Canuck property.

Ed Jovanovski is a defenceman who has been largely ineffective since signing in Phoenix and he comes next. Jovanovski was far more valuable on his previous teams.

Ben Eager had a poor year despite winning the Stanley Cup. He is one of the players that Chicago gave up that won’t hurt them much.

Dustin Brown is well respected as a hitter and for his penalty drawing ability, but he is a poor puck possession player.

This is not a list of the 20 worst players in the NHL by any stretch. There are many aspects of hockey not taken into account by puck possession and these numbers do not include special teams. Also, many of the seldom used goons in the NHL do not get enough playing time to fall to the bottom on a stat like this. Nevertheless, it is not a good sign if your player is on this list. He is not helping his team at even strength.

Comments

Great work, thanks for the insight!
You noted in the top 20 adjusted Corsi that “it is very hard to removed linemate effects from these ratings.” Does adjusted Corsi remain true over years or is the effect of various linemates that significant. As a Canuck fan, it was clear that despite great effort, Ryan Johnson lost a ton of faceoffs in his own end and lost possession due to his poor skating. That would not have helped Tanner Glass or Rick Rypien. Another factor to consider is the negative effect of a poor faceoff percentage on the usual wingers on that line (in this case Glass and Rypien). Just wondering if that factor can be separated out in the analysis. With regards to our latest signing, Mr. Ballard, we can only hope that with his assignment as a 3 - 4 d-man, his skills will not be overstretched.
I must admit that most of us here in Vancouver were very suprised that an individual with the last name of Ballard would ever be signed here. A long time ago, the Canucks had a goalie (Gary Smith) who made an infamous faux pas at the Christmas party to the owner’s wife, whom was the daughter of Dr. Ballard. The comment was something related to her resemblance to the dog on the can. Despite his being a recent Hart trophy nominee, Gary Smith was traded shortly thereafter. Hmmm…. that is a bit of a commentary tangent but there you have it. Cheers

Corsi is about as repeatable as point totals from year to year. A good number of the players on worst Corsi lists this year were there last year (and another sizeable group that was there last year are out of the NHL entirely). Similarly, the top players in the league tend to have good Corsis from year to year - and hence we see the same group of players near the top in back-to-back years.

Like points, things can significantly change if you significantly change the situation in which a player plays. Keith Ballard is a prime example. He goes from being the shutdown defenceman on a bad team to (presumably) a second pairing defenceman on a pretty good team. It will be interesting to see how consistent his numbers are between last year and next. i expect that given a reduced role and better teammates he will do better (i.e. not be on a worst Corsi list) but I doubt he will play as well as the Canucks hope.

Generally a player may be successful if he is transferred into a reduced role, when he was unsuccessful in a previous season. However, the players on this list who find themselves already playing bit roles on their teams have nowhere to go to get reduced roles and stay in the NHL. Hence a player like Kirk Maltby is probably done. There is no sense bringing him back when he is already failing and will be even older next year. I bet you get a better performance by giving a current AHLer his roster spot.